This application is a continuation of U.S. application Ser. No. 15/150,598, filed on May 10, 2016, which is a continuation of U.S. application Ser. No. 14/955,614, filed on Dec. 1, 2015, now U.S. Pat. No. 9,366,356, issued Jun. 14, 2016, which is a continuation of U.S. application Ser. No. 13/756,143, filed Jan. 31, 2013, now U.S. Pat. No. 9,228,672, issued Jan. 5, 2016, which claims priority from Japanese Patent Application No. 2012-021486, filed on Feb. 3, 2012, the disclosures if which are expressly incorporated by reference herein.
The present invention relates to an electromagnetic valve and a fixing structure used for, for instance, a variable valve timing control apparatus of an internal combustion engine.
A related art electromagnetic valve has been disclosed in, for example, Japanese Patent Provisional Publication No. 2010-071359 (hereinafter is referred to as “JP2010-071359”).
This electromagnetic valve is a valve that is provided at a cylinder head of the internal combustion engine and used for supply/exhaust control of working fluid (hydraulic oil) by switching an oil passage of a hydraulic circuit leading to the variable valve timing control apparatus. The electromagnetic valve is formed into a substantially bottomed cylindrical shape, and has a valve body slidably housing, inside thereof, a spool valve body and an electromagnetic solenoid fixed to an axial direction one end portion of the valve body.
The electromagnetic solenoid mainly has a casing that is a cylindrical magnetic material, a coil that is housed and positioned inside the casing, two fixed cores that are provided at axial direction front and rear ends of the casing, a substantially cylindrical column-shaped movable core that is slidably set in a cylindrical member provided at an inner circumference of the coil, and a non-magnetic material driving shaft that is provided at a front end side of the movable core and presses the spool valve body against a spring force of a return spring.
Front and rear ends of a body (a cylinder portion) of the casing are open, and the casing is provided, at the front end side, with a plurality of nail portions formed integrally with the casing. When assembling each component, the fixed core at the front end side is fixed with each nail portion bent inwards.